1. Field of the Invention
The present invention relates to air hose couplers and, in particular, to an improved air hose coupler for use in a tractor-trailer air brake system.
2. Description of the Related Art
Typically, a tractor and its associated trailer incorporate an air brake system that is adapted to provide braking to the wheels of the trailer. Air pressure for the brake system generally is supplied by the tractor, with pressurized air being delivered to the brakes of the trailer through a series of air hoses. The brake system is configured so that when air pressure being supplied to the brakes of the trailer drops below a predetermined level, the brakes apply a braking force to the wheels of the trailer. So configured, a loss of air pressure being supplied by the tractor or a loss of air pressure in the air delivery system should cause the brakes of the trailer to engage, thereby assisting in slowing or stopping the trailer.
Since tractors typically must engage, operate with, and then disengage various trailers, prior art tractor-trailer air brake systems are configured so that the tractors can mateably engage with, and then selectively disengage from various trailers. As is well known in the prior art, connection of the air brake system of a tractor to that of a trailer typically is accomplished by a mateably engagable pair of couplers. Generally, one coupler is attached to the rear of a trailer and is adapted to be engaged by a second coupler or glad hand, which is attached to a tractor.
Connection of couplers typically is facilitated by engaging mating faces of the couplers. Each mating face incorporates an orifice which communicates with an air passage formed through its coupler. At least one of the couplers typically is provided with a gasket so that the gasket is compressed between the mating faces of each coupler during mating, thereby forming an air tight seal between the couplers. Once the mating faces are engaged, the glad hand is rotated relative to the trailer coupler so that a locking plate or paw of the glad hand is engaged between catch plates or catches of the trailer coupler, thereby retaining the glad hand in an engaged position.
In order to manipulate a prior art glad hand into mating engagement with a trailer coupler, the operator of a tractor-trailer typically must grasp the glad hand, such as by its air hose and/or coupler housing. Due to the close proximity of the coupler housing of the glad hand to the engaging portions of the couplers, i.e. the paws and catches, injury to the operator's hands and fingers can result if the operator's hands or fingers slip between the engaging portions of the couplers during engagement. If, however, the operator grasps the air hose or air hose connector, the force applied by the operator in manipulating the glad hand can damage the air hose and/or the connection between the air hose and its air hose connector.
Therefore, there is a need to provide an improved air hose coupler which addresses these and other shortcomings of the prior art.